Science Buddies: "Ask an Expert"

i also need help and its due m=next monday!!! what do i do?

hi angie panda,

I split your post into a new topic so our experts can better help you (and see your questions).

If you are doing the same project as belfry, read the project idea about electrolytes here: https://www.sciencebuddies.org/science- ... p053.shtml

If you do not have a project topic yet, take our Topic Selection Wizard, which will ask you some questions about your interests and then suggest some projects for you:
https://www.sciencebuddies.org/science- ... gister.php

You can also browse our project ideas here: https://www.sciencebuddies.org/science- ... deas.shtml

You should also check out our project guide, which will walk you step by step through doing a project (look at the sections under "How to Do a Science Fair Project" on the left side):
https://www.sciencebuddies.org/science- ... ndex.shtml

Good luck and let us know if you have more questions.

it's not that. I need help on #'s 5-9! I don't get it! Please help me! Due on monday 4/19/10

Please answer me today and fast!!! xD

Do you mean the procedure, parts 5-9? Can you please be more specific? Which parts are you confused about (specifically) and why?

I'm going to get a physical science expert to answer your questions. I'm actually an Expert in life science but I'm a moderator for other sections. In the meantime, take a look at these pages, which go over circuits:

https://www.sciencebuddies.org/science- ... ntro.shtml
https://www.sciencebuddies.org/science- ... eter.shtml

it's not that. I need help on #'s 5-9! I don't get it!

Unfortunately, I don't understand specifically what you are asking about.

If you are referring to this project: https://www.sciencebuddies.org/science- ... p053.shtml,
steps 5 through 9 under "Making a simple conductance sensor" refer to steps in constructing the circuit depicted pictorially in figure 2. The ONLY thing that is missing pictorially is the conductance sensor show in figure 1 is not shown immersed in the container marked "solution with electrolytes". The photograph in figure 2 is also unclear in several respects:
a) The meter is OFF, it should be turned to one of the current scales under the "A" and above the gray marker above the unoccupied place to plug in a test lead for a special scale.
b) The shadows and lighting and placement of things make it hard to see everything in the circuit
c) the plastic piece used is not a hollow tube and looks more like a miniture plastic figure.

There are also steps 5 through 9 under "Measuring the conductance".

Which of these steps and what are you really asking for help with?

In terms of trouble shooting this circuit, I would obtain a 2.7 KOhm resistor and place it across the conductance sensor (one lead of the resistor to one lead of the conductance sensor wire and the other resistor lead to the other end). On the 5 mA scale with a 9 volt battery, you should get about a 3.3 mA indication give or take the tolerance of the resistor (+/- 20% tolerance, +/- 20% of 3.3mA or 2.6 to 4.0 mA) if the rest of your circuit is hooked up correctly.

Other people have had trouble with this project when the conductance of their liquids was too low (resistance too high). An alternate way of doing this experiment is to eliminate the battery and utilize the multi-meter as an Ohm meter. Simply attach the two test leads to the conductance probe and measure resistance. Conductance is the reciprical of resistance. 1 / Conductance = Resistance. 1 / Resistance = Conductance.

For anyone reading this thread, angie panda ended up asking more specific questions in a different thread: https://www.sciencebuddies.org/science- ... =26&t=6073

So please go to that topic for the conclusion to the thread.